Apart from the Army Armament one, they're all good buys.
I have first hand experience with the ICS and the Ares, but I've heard good things about the G&G A2 version as well.
Pros and cons?
The ICS is very well built, very solid, easy to work on, comes with 2 hi caps and great out of the box performance. It also has a quick change spring system, as well as a way to adjust the tension the spring is held under, meaning you can effectively alter the fps without needing a new spring. The hand guard is also made to be airsoft friendly and comes off very easily to reveal space for a large type battery, the others can only fit a small and it takes an age to get it in.
The only downsides of it are that it isn't the most accurate L85 replica out there, the fire selector, trigger guard, colouration of the rubber/plastic furniture and lack of fire indication markings let it down, it also has a quite poorly designed hop up unit, hard hop rubbers simply don't work in it and soft ones don't offer the best range available, so it's all about finding the soft/hard sweet spot.
If you're used to standard config weapons, then the bullpup layout might take a bit of getting used to as well.
The Ares has the pros of flawless externals, it has all the right shaped external controls, the right coloured bits and bobs, the right trigger guard and the fire selector is correctly marked with the A and R as per the real thing. It's the closest AEG L85 there is to the real deal, the general performance is rather good and as with any other AEG, it can be upgraded and tweaked to perform exceptionally well. I'd also dare say the hop unit is probably a lot better than the one in the ICS, but I don't know for sure as I've not looked at it in detail.
Like the ICS the Ares also has a quick change spring system, but it doesn't have adjustable tension.
On the downsides the internals aren't to the same par as the externals (a staple trait of Ares) and it's a nightmare to work on, it also has a polycarbonate gearbox, which many people dislike based on the general belief that plastics aren't quite as strong as metals, as well as only coming with 1 mid cap magazine.
It's also worth noting that if you want to go down the L85 with RIS route, the ICS will take the airsoft made Madbull replica RIS with an adaptor, whereas the Ares will only fit the real steel RIS. The real RIS can probably be had for cheaper these days and it sits in the correct place on the barrel assembly, on the ICS the RIS tends to sit a little higher than on the real thing.
I've never even held the G&G version, but if Airsoft World are anything to go by, it's the most expensive one of the three and it utilises G&G's old, more classic style blowback mechanism, which in case you're unaware is more of a gimmick than anything else, 9/10 people will disable to it prolong the life of the internals. Aside from that I've only heard good things.
I can guarantee that it won't be as easy to take apart as the ICS though. Not sure what mags it comes with, whether or not it comes with a hi cap or a mid, what batteries it fits or anything.
In a nutshell, all are completely different on the inside, completely different animals. But in my opinion, my vote will always go with the ICS. Fire-Support stock all the parts from it in case anything breaks and it's the simplest gun to work on in the universe, I'd never taken a gun apart before I tried it on my ICS and now I've got it shooting as well as anyone could hope for and I know it inside out, I could literally build one from all the individual components.
You'll have me on hand for help, tips and advice should you need them, if you go for the ICS as well. If you look in the review section then I've covered the ICS in pretty spectacular detail in two separate threads.
